Double Loop Pattern Research Articles

Correlation of palatal anatomic characteristics with dermatoglyphic heterogeneity in different growth patterns

The study aimed to explore the correlation between dermatoglyphic patterns and quantitative palatal anatomic variables in individuals with different growth patterns. A cross-sectional study was conducted involving 126 healthy patients aged 17-25 years. Participants were divided into three groups based on growth patterns: average, vertical, and horizontal. Dermatoglyphic patterns were recorded using an optical fingerprint sensor, and palatal characteristics were measured using digital software. Palatal characteristics, including intercanine width, intermolar width, and palatal depth, were measured using digital software. The results were statistically analyzed. Significant differences were observed in ridge counts among the three growth patterns. The average growth pattern showed lower ridge counts compared to the vertical and horizontal growth patterns. Dermatoglyphic patterns, such as double loops and tented arches, were significantly higher in the horizontal growth pattern. Weak correlations were found between certain dermatoglyphic patterns and palatal characteristics, with simple arch patterns showing a negative correlation with inter-canine width and symmetrical whorl patterns showing a positive correlation with palatal depth. Loop patterns, spiral patterns, double loop patterns, symmetrical whorl, and simple arch patterns were significant predictors of growth patterns. This study revealed distinct dermatoglyphic patterns and ridge counts among individuals with different growth patterns. Weak correlations were observed between dermatoglyphic patterns and palatal characteristics. However, the predictive value of dermatoglyphics for skeletal malocclusion requires further investigation. Understanding the relationships between dermatoglyphic patterns and craniofacial growth can provide valuable insights into genetic and developmental factors affecting dental and orthodontic conditions.

Tracing teacher knowledge transformation across multiple levels in collaborative curriculum design: A comparative case study in China

This study, using the knowledge conversion framework, investigated teacher knowledge transformation occurring across individual, group and organization levels when teachers collaboratively design and enact curriculum materials. Participants from two primary schools were interviewed, accompanied by observation of teachers’ classrooms and meetings and collection of curriculum materials. Findings revealed four mechanisms through which teachers’ tacit and explicit knowledge was mutually transformed across the individual (knowledge internalization), group (knowledge externalization and socialization) and organization (knowledge combination) levels. Two different paths of teacher knowledge transformation are summarized: the top-down and unidirectional pattern, and the bottom-up and double-loop pattern. Social-contextual factors that potentially provide explanations, and practical implications are discussed.

The influence of wheelchair propulsion hand pattern on upper extremity muscle power and stress

The hand pattern (i.e., full-cycle hand path) used during manual wheelchair propulsion is frequently classified as one of four distinct hand pattern types: arc, single loop, double loop or semicircular. Current clinical guidelines recommend the use of the semicircular pattern, which is based on advantageous levels of broad biomechanical metrics implicitly related to the demand placed on the upper extremity (e.g., lower cadence). However, an understanding of the influence of hand pattern on specific measures of upper extremity muscle demand (e.g., muscle power and stress) is needed to help make such recommendations, but these quantities are difficult and impractical to measure experimentally. The purpose of this study was to use musculoskeletal modeling and forward dynamics simulations to investigate the influence of the hand pattern used on specific measures of upper extremity muscle demand. The simulation results suggest that the double loop and semicircular patterns produce the most favorable levels of overall muscle stress and total muscle power. The double loop pattern had the lowest full-cycle and recovery-phase upper extremity demand but required high levels of muscle power during the relatively short contact phase. The semicircular pattern had the second-lowest full-cycle levels of overall muscle stress and total muscle power, and demand was more evenly distributed between the contact and recovery phases. These results suggest that in order to decrease upper extremity demand, manual wheelchair users should consider using either the double loop or semicircular pattern when propelling their wheelchairs at a self-selected speed on level ground.

Shoulder pain and jerk during recovery phase of manual wheelchair propulsion

Repetitive loading of the upper limb due to wheelchair propulsion plays a leading role in the development of shoulder pain in manual wheelchair users (mWCUs). There has been minimal inquiry on understanding wheelchair propulsion kinematics from a human movement ergonomics perspective. This investigation employs an ergonomic metric, jerk, to characterize the recovery phase kinematics of two recommended manual wheelchair propulsion patterns: semi-circular and the double loop. Further it examines if jerk is related to shoulder pain in mWCUs. Data from 22 experienced adult mWCUs was analyzed for this study (semi-circular: n=12 (pain/without-pain:6/6); double-loop: n=10 (pain/without-pain:4/6)). Participants propelled their own wheelchair fitted with SMARTWheels on a roller dynamometer at 1.1m/s for 3min. Kinematic and kinetic data of the upper limbs were recorded. Three dimensional absolute jerk experienced at the shoulder, elbow and wrist joint during the recovery phase of wheelchair propulsion were computed. Two-way ANOVAs were conducted with the recovery pattern type and shoulder pain as between group factors. Findings: (1) Individuals using a semi-circular pattern experienced lower jerk at their arm joints than those using a double loop pattern (P<0.05, η2=0.32)wrist;(P=0.05, η2=0.19)elbow;(P<0.05, η2=0.34)shoulder and (2) individuals with shoulder pain had lower peak jerk magnitude during the recovery phase (P≤0.05, η2=0.36)wrist;(P≤0.05, η2=0.30)elbow;(P≤0.05, η2=0.31)shoulder. Conclusions: Jerk during wheelchair propulsion was able to distinguish between pattern types (semi-circular and double loop) and the presence of shoulder pain. Jerk provides novel insights into wheelchair propulsion kinematics and in the future it may be beneficial to incorporate jerk based metric into rehabilitation practice.

Sexual dimorphism in digital dermatoglyphic traits among Sinhalese people in Sri Lanka

BackgroundThe purpose of this study was to evaluate gender-wise diversity of digital dermatoglyphic traits in a sample of Sinhalese people in Sri Lanka.FindingsFour thousand and thirty-four digital prints of 434 Sinhalese individuals (217 males and 217 females) were examined for their digital dermatoglyphic pattern distribution. The mean age for the entire group was 23.66 years (standard deviation = 4.93 years). The loop pattern is observed more frequently (n = 2,592, 59.72%) compared to whorl (n = 1,542, 35.53%) and arch (n = 206, 4.75%) in the Sinhalese population. Females (n = 1,274, 58.71%) have a more ulnar loop pattern than males (n = 1,231, 56.73%). The plain whorl pattern is observed more frequently in males (n = 560, 25.81%) compared to females (n = 514, 23.69%).The double loop pattern is observed more frequently on the right and left thumb (digit 1) of both males and females. Pattern intensity index, Dankmeijer index and Furuhata index are higher in males.ConclusionsUlnar loop is the most frequently occurring digital dermatoglyphic pattern among the Sinhalese. All pattern indices are higher in males. To some extent, dermatoglyphic patterns of Sinhalese are similar to North Indians and other Caucasoid populations. Further studies with larger sample sizes are recommended to confirm our findings.

Genetic studies in varicocele infertility. II: Dermatoglyphic pattern.

The prime concern of the present work was the analysis of dermatoglyphic patterns in infertile patients presenting with clinically detectable varicocele. In a controlled study conducted on 30 patients and utilizing a slight modification of the original ink method of Cummins and Midlo, the dermatoglyphics on terminal phalanges of the thumb in both hands showed significantly higher incidence of the whorl pattern. Likewise, the index finger in both hands exhibited higher incidence of both the whorl and double loop patterns. Other patterns on the fingers, the plamar creases, axial triradii, hypothenar and thenar eminences, and angle and total ridge count did not alter significantly. Such characteristic dermatoglyphic patterns in varicocele infertile men may furnish additional evidence in support of a genetic cause for varicocelogenesis and its associated gonadal dysfunction. Furthermore, it may provide a prognostic preoperative screening method for varicocele infertile patients.

Finite Element Analysis of a Flow Induced by a Rushton Turbine in an Unbaffled Stirred Vessel

A numerical analysis for a flow induced by the Rushton disc turbine was done by a finite element method. As flows in the vessel depend on the geometry of the impellers and the vessels, unstructured mesh was used in order to consider their geometries accurately. Moreover, elements used were a hybrid composed of tetrahedral and prism, which could be resolved boundary layer near the impeller and the shaft. Turbulence models used were k–e and k–ω models and their governing equations were also discretized by the Characteristic-Galerkin method that includes stabilizing terms as well as the momentum equation. Calculated results were compared with the experimental result. The doubleloop pattern in the r–z cross-section could be reproduced by both turbulence models, though with stronger circulation patterns. It was found that the k–ω model could reproduce the Rankin’s vortex qualitatively, while the k–e model could not even qualitatively.

Method to predict isthmus location in ventricular tachycardia caused by reentry with a double-loop pattern

Method to Predict Isthmus Location. Background: During electrophysiologic study, induction and mapping of clinical reentrant ventricular tachycardia can be difficult. Hence, analysis of sinus-rhythm electrograms for reentry localization is of potential clinical relevance. Herein is described a method of sinus-rhythm electrogram shape analysis, that does not require arbitrary threshold values, for localization of double-loop reentrant circuits that drive clinical tachycardias. Methods and Results: Reentrant ventricular tachycardia was induced by premature stimulation in 23 postinfarction canine hearts 4-5 days after left anterior descending (LAD) ligation. Sinus-rhythm activation maps were constructed from bipolar electrograms acquired at 196-312 sites in the epicardial border zone. The timing of all electrogram peak deflections during one cycle of sinus rhythm was determined, and the mean (MPD) and deviation (DPD) were taken, respectively, as estimates of the time of activation wavefront crossing, and the duration of local electrical activity. These variables were then mapped on a computerized grid. The line of most uniform and sharp MPD gradient predicted the propagation direction through the double-loop reentrant circuit isthmus that would occur upon tachycardia induction. The sharpest transitions in DPD bounding this line predicted the positions of arcs of block that would border the reentrant circuit isthmus during tachycardia. The actual and estimated isthmuses overlapped by a mean of 84.1 ′ 3.8%. In six experiments lacking inducible reentrant tachycardia, no line of sharp MPD gradient was present in the MPD maps. Conclusions: Analysis of multiple sinus-rhythm deflections can localize the reentrant ventricular tachycardia isthmus without introduction of arbitrary threshold points and peak choices that may lead to error.

Intermittency and fine structure of velocity fluctuations arising in flow-pattern transitions in stirred tanks

The intermittent velocity fluctuations, induced by a change in the vertical location of the impeller, associated with the double- to single-loop transition in stirred vessels are thoroughly analyzed. It is shown that this type of flow-pattern instability is characterized by a multiscale and nested structure of the velocity fluctuations, in which intermittent bursts pertaining to the two regimes are intermingled in a seemingly “self-similar” way. A filtering procedure based on a Markovian approach grounded on the definition of a transfer probability matrix is proposed in order to deconvolute from the original time series the nested intermittent bursts corresponding to local single- and double-loop patterns. This technique permits to define and estimate macroscopic statistical properties, such as the average burst duration in one of the two-regimes, and the frequency that characterizes this type of flow pattern intermittency. A heuristic analysis of the dynamic origin of the flow-pattern transitions in terms of global bifurcations and attractor crisis is addressed.

Radiation Damage Effects in Ferroelectric Triglycine Sulfate

Peculiar changes in the ferroelectric hysteresis loops of single crystals of triglycine sulfate result when the crystals are subjected to ionizing radiations (x-rays and electrons). Fully polarized crystals develop hysteresis loops biased along the field axis while partially polarized crystals develop double-loop patterns, each subsidiary loop being biased to the same extent but in opposite directions. The biased loops retain their rectangularity during the early stages of the bombardment. The bias field builds up steadily during the bombardment while the reversible polarization shows no change at first but eventually, at a fairly well-defined value of the bias field, it begins to decay in a fairly rapid manner.Unusual field- and temperature-dependent changes in the shapes of the "damaged" hysteresis loops are observed. Under certain conditions, a double-loop pattern will "anneal" into a normal single loop simply as a result of applying the ac field; but when the field is removed, the crystal relaxes back to its double-loop form. Such cycles can be repeated, apparently indefinitely, provided that the field is not removed for too long a period. If this happens, the double-loop pattern fails to respond to further field treatments though it can be returned to the more unstable state by gentle heat treatment of the crystal.The experiments rule out explanations of the effects based on the setting up of space charge fields or on nonuniform damaging of the crystal. It seems most likely that the effects are caused by the gradual building up of a more or less uniform strain in the crystal. The results are discussed in terms of the conventional double-minimum potential energy curve used for describing ferroelectric mechanisms. On the basis of some pyroelectric studies, however, it appears that a rather more complicated potential energy curve is needed to describe ferroelectricity in triglycine sulfate.It is pointed out that, as the x-ray dosages required to produce large changes in the ferroelectric properties are small compared with those usually used in crystallographic structure determination, it seems most unlikely that the structure of an undamaged triglycine sulfate crystal has yet been determined, and one wonders how true this may be of certain other structure determinations for radiation-sensitive organic crystals.